ZMR250 PDB Bottom Plates Options – Diatone, Overcraft, Nucleus

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Many mini quad frames come with built-in PDB (power distribution board) bottom plates, which saves quadcopter builders a lot of time and troubles. ESC’s, Battery connector, even your FPV system can be soldered directly on to the PDB, that keeps the use of wires to the minimal. This not only reduces weight but also makes a super clean build.

The ZMR250 frame does not come with any PDB, so many options have been released as upgrade. In this post we will focus on 3 popular power distribution boards for the ZMR.

SimplePDB By OSO

cytrynka PDB

Description from developer: cytrynka is an all-in-one power distribution board (PDB) with some extra components to make your racing machine clean and light. The most important objective in the design was to create board to eliminate cables/wires as much as possible. cytrynka consists of two parts – main board (replacement for original top main plate) and conversion board to direct fit most popular FC’s (ex. NAZE32, CC3D). It fits into ZMR250, RCX250 and QAV250 (chinese version) frames.

Here is my full review on this PDB: https://oscarliang.com/cytryna-pdb-zmr250-frame/

Diatone ZMR250 PDB

The Diatone PDB was just released last month. The price is only $6 from Banggood. It weights 35g, PCB is 1.6mm thick.

Warning (16 Jun 2015): It’s been reported that this PDB, screw holes doesn’t fit most of the ZMR250 frame on the market. So make sure you get the measurement from seller, and check on your frame before purchase.

This is a relatively simple power distribution board, compared to the other 2 in this article. But it also has integrated 5V and 12V voltage regulators, which is safe to assume this board is designed for 3S, as well as 4S LiPo setup. It enables you to convert voltage from 4S to 12V for your FPV gear. But as these are step down regulators, if you are only running 3S Lipo and your voltage drops below 12V, your 12V regulator output will always be slightly lower than your lipo voltage, any would not be 12V.

5V output can be used to power your flight controller and radio. This is useful if you are running Opto ESCs that don’t have a BEC.

It also comes with 4 LED strips, which you can solder on the PDB to help with your orientation when flying LOS.

It doesn’t have any power filter built-in, so bear in mind if you encounter any horizontal jumping lines in your FPV footage, you can put a LC filter (power filter) on this PDB.

One thing that remains unclear is how much current this PDB can handle, it’s not mentioned on the product page.

I ordered this board recently, hopefully I can write a more in-depth review once it’s here.

Overcraft PDB

The Overcraft PDB is pretty powerful and has almost everything you ever need on the PDB. It weights 35g, and PCB is 1.6mm thick. Here are some of the features that the Diatone PDB doesn’t offer.

FPV Filter (on both 12V and 5V outputs)

MinimOSD integration – can be soldered directly on PDB.

Solder pads and Traces for FPV Camera, Video transmitter

Built-in Buzzer

However it doesn’t have a 12V regulator for 4S, but there is an optional soldering pad for external voltage regulator if you need one.

This PDB is pretty cheap ($8) and extremely hard to get hold of. It’s only being made once every two months I think, sales usually announced on RCGroup.

NUCLEUS ZMR250 PDB

This board has almost identical features to the Overcraft PDB, but its price tag is way higher at $27. It weights 34g, and PCB is 1.6mm thick. The available connection locations really help keeping it wire-free and tidy.

There are some difference compared to the Overcraft though.

Power filter on this PDB requires soldering.

Location of the ESC solder pads

Bigger, brighter LEDs

LEDs are turn off by default

Smaller / slightly quieter buzzer

Price difference!

This board can be found here. But I personally would go for the Overcraft over this PDB due to the much lower price.

Here are my questions:
1. According to the holes pattern for the micro minimOSD how should I solder it to the board and still be able to flash / program it latter it I need to?
2. Can I connect the OSD & Bluetooth programmer to the TX RX port on the board at the same time?
3. I plan to solder the stackable female pins on these board instead of solder the FC & OSD etc directly to the board. Is there a pros & cons for each approach that I should be aware of?
4. There aren’t much documentation available for this board can I assume that the only wires that I have to solder to this board are: 1. Power source 3 or 4S. 2 Camera. 3 VTX. 4 PPM wire from the FC to the receiver?

Alan,
1. check out my build log on the ZMR250 V2, how I install the MinimOSD, that way i still able to flash firmware on the Minim.
2. no you can’t.
3. height is the only concern. if you can manage that there is no problem.
4. Buzzer, 5V voltage regulator if you don’t have ESC BEC, 12V voltage regulator for your FPV gear

Hi Oscar,
I’m new to this and I building my first quad with help of my friend who is more experienced. But he was unable to help with power issues I have. I have the Diatone ZMR 250 PDB v2.1 which have a possibility to connect ESC signal directly to PDB directly next to frame shoulder where ESC is. Also have a of course main power for ESC on the PDB on the same place. So saving almost all wires going from ESC. But this leads me to to my problem. What about the “signal ground” wire going from ESC? From my point I have 4 options and all forums have different opinion about this so I hope you can help me resolve my issue for good. So do I need to:
a) lead the “signal ground” all the way to FC (Flip32) for all 4 ESC?
b)lead the “signal ground” all the way to FC (Flip32) for 1 ESC and rest of them cut or make as point c)
c) lead “SG” only to Ground on PDB where the main ground of ESC is connected
d) I don’t need the “SG” at all and I can cut these wires on all 4 ESC
Obviously I prefer c) or d) to have minimum wires :)
My ESC is Hobbywing XRotor 20A ESC 3-4s for RC Multicopters for DJI RC Quadcopter Multicopter

HI Martin, you definitely need Signal ground to ensure least noise signal. It’s especially important if you are running Oneshot where the signal width is much much smaller than PWM.
Go for option C – connect signal ground to ESC power ground.

Thanks for reply Oscar. Maybe as well a dumb questions but I noticed it only now. If I go ahead with option c) the main ground for ESC is I guess 12V where “SG” normally goes to FC which is 5V. So wouldn’t this be a problem……..

in an ideal world, all grounds in an electronics system should be connected, as voltage is measured with ground as reference. So 5V is 5V, 12V is 12V because they have the same ground. So you don’t need to worry about it.
But your concern is reasonable, there could be noise on the 12V system as your motor can create lots of noise, and it might not be so bad on the 5V system as it’s regulated, that can affect your signal if your SG is connected to the ESC GND and not the FC GND… Whenever possible, connect SG to FC GND… but I have been connecting SG to the ESC GND and haven’t had any problems..

I am running the diatone PDB on 4s for a few weeks now with no issues at all. Its a great board and I had my doubts at first but have been impressed. You cant beat this board for the price. I may use it with a NAZE + OSDOGE setup for a super clean build.

It is a shame that they put only 500mamp (0.5Amp) regulators on the board so be careful what you connect. Also the necessary capacitors are missing for the voltage regulators so i solder smd ones between the legs.

Thanks, this writeup is useful. I got sick of the ‘rats nest of wires’ approach and used a square PDB for my last rebuild. I was looking for a PDB like the ones described, but could not for the life of me find anyone with one in stock for the several weeks I spent looking. I’ll use this as a resource the next time I think I’ll need a rebuild!

Just before I purchased the ZMR250 frame with a 36×36 pdb and a 12v step down regulator you came with the diatone pdb! Gonna get this instead and look how things go. Your blog is awesome! :)
Greets
MUuuulerOriginal from Youtube. ;P